Mold-Spraying Apparatus of Molding System

ABSTRACT

Disclosed is a method of a mold-spraying apparatus for use with a molding apparatus. The mold-spraying apparatus has: (i) a spray nozzle, (ii) a rotatable shaft being supportive of the spray nozzle, and (ii) a camming surface. The method includes: (a) engaging the rotatable shaft with the camming surface, and (b) moving the camming surface so that the rotatable shaft may rotate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a continuation patent application of a priorU.S. patent application Ser. No. 11/494,313, filed Jul. 27, 2006. Thispatent application is a continuation of 11/690,161, filed Mar. 23, 2007which is a continuation of parent application No. 11/494,313 filed Jul.27, 2006.

TECHNICAL FIELD

The present invention relates, generally, to molding systems, and moreparticularly, but not exclusively, the present invention relates to: (i)a mold-spraying apparatus of a molding system and/or (ii) a moldingsystem having a mold-spraying apparatus, and/or (iii) a method of a moldspraying apparatus of a molding system, and/or (vi) a method of amolding system having a mold-spraying apparatus, amongst other things.

BACKGROUND

U.S. Pat. No. 4,976,603 (Inventor: Disimone; Published: 1990-12-11)discloses a device for removal of moldings from injection-moldingmachines. The device utilizes a suction cup rotating about a verticalshaft to hold and remove the molding.

U.S. Pat. No. 6,192,968 (Inventor: Renkl et al; Published: 2001-02-27)discloses preparing mold walls ready for the next molding cycle afterremoval of molded part.

U.S. Pat. No. 6,857,463 (Inventor: Jordan et al; Published: 2005-02-22)discloses a spraying system for applying one or more materials to anopen mold within a molding machine. The spraying system has a sprayhead, a manipulator, a supply of materials, a conduit, apressure-boosting device, and a control device.

U.S. Pat. No. 6,938,669 (Inventor: Suzuki et al; Published: 2005-09-06)discloses injection molding of metal products that involves heating atip of hot runner, spraying a lubricant onto a molding surface andmetering material, simultaneously between mold clamping and pressurizingprocesses.

SUMMARY

According to a first aspect of the present invention, there is provideda method of a mold-spraying apparatus for use with a molding apparatus,the mold-spraying apparatus having: (i) a spray nozzle, (ii) a rotatableshaft being supportive of the spray nozzle, and (ii) a camming surface,the method including: (a) engaging the rotatable shaft with the cammingsurface, and (b) moving the camming surface so that the rotatable shaftmay rotate.

According to a second aspect of the present invention, there is provideda method of a mold-spraying apparatus of a molding apparatus, themolding apparatus having: (a) a fixed platen, (b) a movable platen, (c)a platen-moving mechanism being configured to move the movable platenrelative to the fixed platen, and (d) a mold having molding surfacesbeing supported by the fixed platen and the movable platen, and the molddefining a mold envelope, the mold-spraying apparatus having: (i) aspray nozzle, (ii) a rotatable shaft being rotatably mounted to thefixed platen, the rotatable shaft being attached to the spray nozzle,(iii) a camming surface being movable with the movable platen, (iv) acam follower being attached to the rotatable shaft, and the cam followerbeing engageable with the camming surface, the method including: (a)actuating the platen-moving mechanism so that the movable platen may bemoved; and (b) engaging the cam follower with the camming surface sothat the rotatable shaft and of the spray nozzle may be rotated, and thespray nozzle becomes: (I) rotated proximate of the molding surfaces tospray the molding surfaces when a movable portion of the mold beingattached with the movable platen becomes separated from a fixed portionof the mold being attached with the fixed platen, and (II) rotated to aposition outside the mold envelope before the movable portion of themold makes contacts the fixed portion of the mold.

A technical effect, amongst other technical effects, of the aspects ofthe present invention is an improved mold-spraying apparatus. Preferableembodiments of the present invention are subject of dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the exemplary embodiments of the presentinvention (including alternatives and/or variations thereof) may beobtained with reference to the detailed description of the exemplaryembodiments of the present invention along with the following drawings,in which:

FIG. 1 is a perspective view of an injection molding machine having amold-spray apparatus in accordance with a first exemplary embodiment;

FIG. 2 is a schematic representation of the mold-spray apparatus of FIG.1 shown in an open mold position;

FIG. 3 is a schematic representation of the mold-spray apparatus of FIG.1 shown in a closed mold position;

FIG. 4 is a plan view of a portion of a mold and the mold-sprayapparatus of FIG. 1;

FIG. 5 is a schematic top view of the mold-spray apparatus of FIG. 1;

FIG. 6 is a perspective view of an injection molding machine having amold-spraying apparatus according to a second exemplary embodiment;

FIG. 7 is a side schematic view of mold-spray mechanism of FIG. 6; and

FIG. 8 is a plan schematic view of the mold-spraying mechanism of FIG.6.

The drawings are not necessarily to scale and are sometimes illustratedby phantom lines, diagrammatic representations and fragmentary views. Incertain instances, details that are not necessary for an understandingof the embodiments or that render other details difficult to perceivemay have been omitted.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

FIG. 1 is a perspective view of an injection molding machine 1 (which isan example of a molding system for a molding machine), the injectionmolding machine 1 has a mold-spray apparatus 2 in accordance with thefirst exemplary embodiment. The molding machine 1 and the mold-sprayingapparatus 2 may be sold separately or may be sold in combination. Themold-spraying apparatus 2 includes a rotatable shaft supportive of aspray nozzle.

Preferably, upon rotation of the rotatable shaft, the spray nozzlebecomes positionable proximate of a mold of the molding systemsufficiently enough so that the mold becomes sprayable by the spraynozzle. The injection molding machine 1 includes tie bars 3, a clampcolumn 5 on a machine frame 7. A fixed platen 9 and movable platen 10are situated on the machine frame 7 in a manner well understood in theart. The movable platen 10 is guided along rails 12 between mold openand closed positions. A stationary mold half 14 is bolted or otherwisemounted on fixed platen 9. A movable mold half 16 is similarly mountedon movable platen 10. When the mold is closed the two mold halves 14 and16 create the necessary molding space in a manner well understood in theart.

When molding it is often necessary to treat the mold before performing amolding operation. Depending on the materials being used in the moldingoperation, it is sometimes necessary to clean the mold after eachmolding operation by washing the mold with water or air or some othercleaning solution. In other instances, it may be necessary to treat themold with a non-welding or release agent to ensure that the molded partdoes not weld or stick to the mold. In the past, these pretreatmentprocedures have required elaborate and complex devices to ensure thatthe molding surfaces are uniformly and consistently treated. Theexemplary embodiment provides a simple, but reliable, apparatus andprocess for delivering the required material to the mold surfacesreliably.

As shown in FIG. 1, this apparatus includes a pair of cams 18 and 19 andcam followers 21 and 22. The cam followers 21 and 22 are attached torotatable shafts 24 and 25, respectively. The shafts 24 and 25 may bemounted on the mold, platen or machine in a position to be rotated bythe movement of the cams 18 and 19 on the movable platen 10. Thedetermination as to where to mount the shafts 24 and 25 may bedetermined by the type of mold that is being used. For example, if aparticular mold is one of a number of very similar molds where thecavities are the same in number and in substantially the same positionwithin the mold, it may be acceptable to locate the shafts 24 and 25 onthe fixed platen 9 or on the movable platen 10. If the particular moldis unique in that it may have more cavities or cavities that aresubstantially different from any other mold then it may be appropriateto mount the shafts 24 and 25 on one mold half. In the embodiment shownin FIG. 1, the shafts 24 and 25 are mounted on the stationary mold half14 since the mold shown is a four cavity mold that is one of manysimilar molds.

The shafts 24 and 25 extend from rotary manifolds. Only rotary manifold27 can be seen in FIG. 1. The rotary manifolds provide air or lubricantor other desired fluids to tubes within the shafts 24 and 25 to deliverthe fluids to nozzles connected to the shafts 24 and 25 located atpre-selected positions along the shafts 24 and 25. The pre-selectedpositions are determined by the cavity placement within the mold. Therotary manifolds also include lubricating bearings in order to allowease of rotation for the shafts 24 and 25.

As shown in FIG. 1, nozzles 29 and 30 are mounted on mounting blocks 32and 33, respectively. The nozzle mounting blocks 32 and 33 are mountedon shaft 25 and provide support for nozzles 29 and 30 and fluidcommunication between the shaft 25 and the nozzles 29 and 30. A similararrangement of nozzles and mounting blocks is situated on the shaft 24but is not visible in FIG. 1.

The nozzles 29 and 30 on the shafts 24 and 25 are moved into and out ofthe mold as the shafts 24 and 25 rotate. As shown in FIG. 1, the mold isopen with the nozzles located between the molding faces. In thisposition, each cam follower 21 and 22 is in its innermost positionagainst the cam surface of the respective cam 18 or 19. When the movableplaten 10 is in motion to close the mold the cam followers 21 and 22travel along the cam surface of the respective cam 18 or 19. This motionof the cam followers 21 and 22 rotates the shafts 24 and 25. This actionrotates the attached nozzles from a position between the mold faces to aposition outside the mold when the mold is closed so that the nozzles donot interfere with the mold during a molding operation.

FIG. 2 is a schematic representation of the mold-spray apparatus 2 ofFIG. 1 shown in an open mold position. FIG. 3 is a schematicrepresentation of the mold-spray apparatus 2 of FIG. 1 shown in a closedmold position. In FIG. 2 the mold is in the open position with thenozzles positioned between the mold faces. In FIG. 3 the mold is closedand the nozzles are situated outside the mold. For ease of reference,similar elements in FIGS. 1, 2 and 3 will be referenced with the samereference number. FIGS. 2 and 3 illustrate, schematically, the operationof the nozzle positioning system located on the side of the moldobscured by the movable platen 10. As shown in FIG. 2, the mold formedby mold halves 14 and 16 is open with the movable platen 10 in the moldopen position.

A cam plate 31 is attached to the movable platen 10 by bolts 34 and 36.A cam groove 35 is formed in the cam plate 31. In this illustration, thecam surface is provided by a groove to better retain the cam follower22. As shown in FIG. 1, the cam surface is open. Each design has itsadvantages and disadvantages. With the open surface, it is relativelyeasy to retract the nozzles into a position where the nozzles may beserviced or replaced. The shaft can be rotated with relative ease byapplying a torque on the shaft and rotating it in a position where itcan be serviced. However, the open groove makes it somewhat moredifficult to restrain the cam follower within the desired travel pathsince the cam follower may lose contact with the open surface, andfurthermore, the cam follower and shaft will need some sort of biasingmechanism in order to actuate the rotation of the shafts 24 and 25 backto the starting position once the cams rotate them out of the mold. Withthe grooved cam surface the cam follower is readily retained within thedesired travel path but servicing and replacement of the nozzles isslightly more complicated since the cams cannot simply be rotatedoutside of the assembly due to the grooves they lie in. In order toservice, the cams can only be rotated by movement of the mold halvesrelative to each other, meaning more energy and power consumption duringservice periods or dismounting the cam plate from the platen.

Rotatable shaft 24 is positioned in relationship to mold half 14 bythree mounting blocks 38, 39, and 40. Each mounting block 38, 39 and 40includes a bearing surface to permit the shaft 24 to rotate within themounting block. Of course, the number of mounting blocks can be variedto suit the circumstances. For a large complex mold more mounting blocksmay be required whereas for a simple mold two may be sufficient.

The base of shaft 24 is connected to a rotary manifold 42 and providessupport for the shaft 24 and a fluid connection to the shaft 24 from afluid source connected to the hose 44. The shaft 24 has a supply channelconfigured to supply a spraying material to the spray nozzles 51, 58,60, 61. The hose 44 preferably engages the manifold 42, the manifoldpreferably being mounted rigidly on the frame 7 of the molding system 1.The manifold 42 contains bearings in order to allow rotation of theshaft 24 without rotation of the manifold 42 relative to the moving andstationary platens. The hose 44 supplies fluid to the manifold 42 whichthen transfers the fluid to the supply channel of the rotating shaft 24.

The top end of shaft 24 is firmly attached to a cam follower arm 46. Camfollower arm 46 extends towards cam groove 35. Cam follower 22 isattached to one end of arm 46 and extends into groove 35 and is confinedto movement within the groove 35.

As shown in FIG. 2, two nozzle mounting blocks 48 and 49 are firmlyattached to rotatable shaft 24. Fluid channels (not shown) within eachblock 48 and 49 connect to fluid channels (not shown) within the shaft24 and provide fluid connections to the support and supply rods 51 and52. The rods 51 and 52 support nozzle connectors 54 and 55 and enablefluid connections through to connectors 54 and 55.

The nozzles 57 and 58 are attached to nozzle connector 54 and nozzles 60and 61 are attached to nozzle connector 55. When the nozzles are in theoperative position shown in FIG. 2, the nozzle 57 is in position tospray fluid onto the cavity 63 and nozzle 60 is in position to sprayfluid onto the cavity 64 in the fixed mold half 14. Similarly, nozzles58 and 61 are in position to spray liquid onto molding surfaces (notshown) on movable mold half 16.

The controls and actuation devices for operating the nozzles are wellknown to those versed in injection molding technology and are notdescribed herein nor do they form a part of the exemplary embodiment.The exemplary embodiment is primarily concerned with providing aninexpensive and reliable system for positioning nozzles within an openmold and retracting the nozzles from within the mold before it isclosed.

As will be apparent to those skilled in the art, the shape of the camsurface may be significantly different for different types of parts anddifferent molding machines. The speed with which the arms must bewithdrawn from within the mold is influenced, at least in part, by theinjection cycle speed of the machine. The size or profile of the partinfluences, at least in part, the separation of the mold faces when themold is open. This separation will influence the shape of the camsurface as it will put a limit on the space available to rotate thenozzles in and out of the mold. One parameter of the cam profile is thecam length. Depending on the mold stroke length, the cam length willcontrol the speed at which the shaft 24 rotates. The second majorparameter is the groove 35 profile. The groove 35 profile isinstrumental in controlling the rate of rotation of the shaft. Dependingon the profile, the shaft may rotate at a slow speed or at a high speeddepending on the mold stroke length.

FIG. 3 illustrates, schematically, the nozzle positioning system withthe mold closed. As shown, the mold faces on the fixed and movable molds14 and 16 are in sealing engagement and the nozzles 57, 58, 60 and 61are in a retracted position alongside the movable mold 10. The shaft 24has rotated approximately ninety degrees by rotation of the arm 46. Thecam follower 22 caused arm 46 to rotate as it followed the groove 35 asthe movable platen 10 was moved towards the mold closed position.

FIG. 4 is a plan view of a portion of a mold and the mold-sprayapparatus 2 of FIG. 1. FIG. 4 is a plan view within the middle of themold facing toward the movable mold half. Like parts on FIG. 4 arereferenced with the same reference characters as are used on FIG. 1. Thecavities 66 on the fixed mold half preferably form covers for mobiletelephone sets when the mold is closed. Cams 18 and 19 are located abovethe platen 10 (not shown in FIG. 4). The shaft 24 extends throughmounting blocks 68 and 69. Shaft 25 extends through mounting blocks 70and 71. Each mounting block 68, 69, 70 and 71 includes bearings 73 topermit rotation of the shafts 24 and 25. Shafts 24 and 25 are supportedin rotary manifolds 75 and 27. The fluid to be sprayed on the molds istransferred through the rotary manifolds 75 and 27 and to the hollowshafts 24 and 25 coupled to the manifolds by bearings 73. Once the fluidis in the shafts 24 and 25, the fluid travels upward towards the nozzlebodies and through each nozzle.

Cam followers 21 and 22 extend upwards from cam follower arms 77 and 78,respectively, and engage a cam surface on cams 18 and 19, respectively,as best shown in FIG. 1.

FIG. 5 is a schematic top view of the mold-spray apparatus 2 of FIG. 1.FIG. 5 is a top schematic view illustrating the positioning of thesprayer heads during mold spraying, mold closure and sprayer headreplacement or repair. When the shafts 24 and 25 have rotated thesprayer arms 51 and 29 into position A the nozzles 57, 58, 77 and 78 arein position to spray the corse and/or the cavities in the mold. When theshafts 24 and 25 are rotated into position B (only shaft 24 shown inthis position) the nozzles 57, 58, 77 and 78 are in a parked positionalong the outside of the movable platen 10. When the shafts 24 and 25are rotated into position C (only shaft 25 shown in this position) thenozzles 57, 58, 77 and 78 are in a readily accessible position forservicing or replacement of the nozzles. The same positions A, B, and Care attainable with the grooved cam configuration of FIG. 2, only inorder to attain position C, the cam follower 22 and cam 46 would need tobe extracted out of the groove 35 and rotated into position C.

FIG. 6 is a perspective view of an injection molding machine having amold-spraying apparatus according to a second exemplary embodiment. Therotatable shafts for rotating the spray heads into and out of the moldare located in a horizontal plane rather that a vertical. The cams 80and 81 are mounted on the side of the movable mold half 16 and therotatable shafts 83 and 84 are mounted at the top and the bottom of thefixed mold half 14. In this embodiment the spray head assemblies 86 and87 are rotated upwardly out of the mold when the mold closed by theaction of cam follower 91 moving along cam surface 92. Likewise, sprayhead assemblies 89 and 90 are rotated downwards when the mold closes bythe action of cam follower 94 moving along cam surface 95.

FIG. 7 is a side schematic view of mold-spray mechanism of FIG. 6; FIG.8 is a plan schematic view of the mold-spraying mechanism of FIG. 6. Asingle shaft is used to rotate sprayer heads into and out of the mold.FIG. 7 is a side view of the apparatus and FIG. 8 is a plan viewdirected toward the fixed platen. FIG. 7 shows a single rotatable shaft97 with a nozzle connector arm 98. The arm 98 is illustrated in thethree positions A, B and C. In position A the spray nozzles 100 and 101are in position to spray the cores and/or the cavities in the mold, inposition B the nozzles 100 and 101 are in a parked position outside themold and in position C the nozzles 100 and 101 are in a serviceposition. This is similar to the positioning of nozzles illustrated inFIG. 5 and operates in the same manner as the operation described withreference to FIG. 5

Additionally FIG. 7 shows the release of a part 102 from movable moldhalf 16 by ejector mechanism 104 on movable platen 10, a fixed mold half14 on fixed platen 10 and tie bars 3.

FIG. 8 is similar to FIG. 4 except that only a single rotatable shaft isrequired. Elements that correspond between the two figures have beenidentified by the same reference characters. The description given withreference to FIG. 4 adequately describes the structure and operation ofthese common components.

FIG. 8 additional shows a runner 106 and three sets of sprayer headassemblies 108, 109 and 110. The runner provides a path for theinjection material as is well known in the industry. The three sets ofsprayer heads are configured to spray fluid on three adjacent moldsurfaces located on the movable platen and stationary platen. Accordingto a variant, more than three or less than three sprayer heads are useddepending on the number of cavities in the working mold.

The description of the exemplary embodiments provides examples of thepresent invention, and these examples do not limit the scope of thepresent invention. It is understood that the scope of the presentinvention is limited by the claims. The exemplary embodiments describedabove may be adapted for specific conditions and/or functions, and maybe further extended to a variety of other applications that are withinthe scope of the present invention. Having thus described the exemplaryembodiments, it will be apparent that modifications and enhancements arepossible without departing from the concepts as described. It is to beunderstood that the exemplary embodiments illustrate the aspects of theinvention. Reference herein to details of the illustrated embodiments isnot intended to limit the scope of the claims. The claims themselvesrecite those features regarded as essential to the present invention.Therefore, what is to be protected by way of letters patent are limitedonly by the scope of the following claims:

1. A method of a mold-spraying apparatus for use with a moldingapparatus, the mold-spraying apparatus having: (i) a spray nozzle, (ii)a rotatable shaft being supportive of the spray nozzle, and (ii) acamming surface, the method comprising: engaging the rotatable shaftwith the camming surface; and moving the camming surface so that therotatable shaft may rotate.
 2. The method of claim 1, wherein: uponrotation of the rotatable shaft, the spray nozzle becomes positionableproximate of a mold of a molding system sufficiently enough so that themold becomes sprayable by the spray nozzle.
 3. The method of claim 1,further comprising: positioning the rotatable shaft relative to a mold.4. The method of claim 1, further comprising: connecting the rotatableshaft with a mechanism being actuatable to rotate the rotatable shaft.5. The method of claim 1, further comprising: connecting the rotatableshaft with a mechanism being actuatable to rotate the rotatable shaftduring opening and closing of a mold.
 6. The method of claim 1, furthercomprising: connecting the rotatable shaft with a mechanism beingactuatable to rotate the rotatable shaft: (i) within a mold envelop of amold after the mold is opened, and (ii) outside of the mold envelop ofthe mold before the mold is closed.
 7. The method of claim 1, furthercomprising: supplying a spraying material to the spray nozzle.
 8. Themethod of claim 1, further comprising: camming the rotatable shaft sothat the rotatable shaft rotates.
 9. The method of claim 1, furthercomprising: rotating the rotatable shaft so as to rotate the spraynozzle into a mold envelope of a mold after a movable-mold portion and afixed-mold portion of the mold are separated from each other.
 10. Themethod of claim 1, further comprising: rotating the rotatable shaft torotate the spray nozzle into a mold envelop of a mold as a movable-moldportion and a fixed-mold portion of the mold are separating from eachother.
 11. The method of claim 1, further comprising: rotating therotatable shaft to rotatably retract the spray nozzle from a moldenvelop defined by a mold before a movable-mold portion and a fixed-moldportion of the mold are closed against each other.
 12. A method of amold-spraying apparatus of a molding apparatus, the molding apparatushaving: (a) a fixed platen, (b) a movable platen, (c) a platen-movingmechanism being configured to move the movable platen relative to thefixed platen, and (d) a mold having molding surfaces being supported bythe fixed platen and the movable platen, and the mold defining a moldenvelope, the mold-spraying apparatus having: (i) a spray nozzle, (ii) arotatable shaft being rotatably mounted to the fixed platen, therotatable shaft being attached to the spray nozzle, (iii) a cammingsurface being movable with the movable platen, (iv) a cam follower beingattached to the rotatable shaft, and the cam follower being engageablewith the camming surface, the method comprising: actuating theplaten-moving mechanism so that the movable platen may be moved; andengaging the cam follower with the camming surface so that the rotatableshaft and of the spray nozzle may be rotated, and the spray nozzlebecomes: (i) rotated proximate of the molding surfaces to spray themolding surfaces when a movable portion of the mold being attached withthe movable platen becomes separated from a fixed portion of the moldbeing attached with the fixed platen, and (ii) rotated to a positionoutside the mold envelope before the movable portion of the mold makescontacts the fixed portion of the mold.